Question

I have a website with a join form that asks you for your country and then city.
When you type your city it sends AJAX calls back to a MySQL DB I have and this returns 10 possible results in a div under the input that you can select from or type further for a more refined return.

This works fine for one country (I purchased this DB) but I need to expand it for the entire world.
I can purchase a DB for the world (country, city, suburb, postcode, geo co-ordinates) but its not cheap so I wanted to ask.

1. Is there a way to do the same thing using Google Maps, Yahoo or Bing? Can I have users enter a country city location and have the GEO CO-Ords returned? Is it possible to do this with the AJAX keyup event returning possibilities?

2. How to other people/sites go about this.

Note: I should also explain why I need this. The site is for online dating and I need to do radius searches. Eg: search for other members within 10KM or 20KM from where I am so I need GEO CO-Ords for each member.

Any advice would be greatly appreciated.

Answer 1

I have used Geonames in my previous geo-based project, what I did was:

1. Downloaded the free database from the site.
2. Imported the country, city, admin area database.
3. Created my own Ajax service and various functions based on the imported database.

To make a query quick enough for your auto-complete input form, you might want to reduce the data size of the cities table by eliminating less populated cities by using “cities1000.zip” (which stands for “all cities with a population > 1000). I used this solution and the search speed was at least 1000x times faster.

And a quick answer for your “radius searches”, you can use these Reverse Geocoding Webservices from Geonames as well.